diff --git a/ChangeLog b/ChangeLog
index 64f4b1ad..cbae3bed 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+2005-09-19  Akim Demaille  <akim@epita.fr>
+
+	* NEWS, configure.ac: Bump to 2.1a.
+
 2005-09-16  Paul Eggert  <eggert@cs.ucla.edu>
 
 	* NEWS: Version 2.1.
diff --git a/NEWS b/NEWS
index 5ce98639..9523191d 100644
--- a/NEWS
+++ b/NEWS
@@ -1,6 +1,8 @@
 Bison News
 ----------
 
+Changes in version 2.1a:
+
 Changes in version 2.1, 2005-09-16:
 
 * Bison-generated parsers now support the translation of diagnostics like
diff --git a/configure.ac b/configure.ac
index cf6b6880..037f2672 100644
--- a/configure.ac
+++ b/configure.ac
@@ -23,7 +23,7 @@
 # least Autoconf 2.59.
 AC_PREREQ(2.59)
 
-AC_INIT([GNU Bison], [2.1], [bug-bison@gnu.org])
+AC_INIT([GNU Bison], [2.1a], [bug-bison@gnu.org])
 AC_CONFIG_AUX_DIR([build-aux])
 AC_CONFIG_MACRO_DIR([m4])